Adjustable reamer.



K). P. HOWK.

ADJUSTABLE REAMER.

APPLICATION FILED JUNE 5. ms.

lu m 3 @MJMM m 7 m a k 1w CHARLES P. HOWK, 0F WORCESTER, MASSACHUSETTS.

ADJUSTABLE. REAIVL'ER.

menace.

Specification. of Letters Patent.

Patented Jan. 7,19itl.

Application filed June 5, 1918. Serial No. 2383M.

To all whom it may concern:

Be it. known that l, CHARLES P. Hown, a citizen of theUnited States, residing at Worcester, in the county of Worcester and State of Massachusetts, have. invented new and useful Improvements in. Adjustable Reamers, of which the following is; a 1 speciiication.

This invention relates. toreamers and has for its object to furnish an adjustable reamer having certain new and useful features, including those of a pair of blades Which are adjustable simultaneously, the radial arrangement of the blades with respect to. the head or holder therefor, and means for mounting the blades so. thatthey center themselves. with respect to the hole being reamed yet at the same time are, rigid in the directions: where rigidity is required in order to properly perform their cutting function. H p

The preferred embodiment of 1nyinven tion is shown in the accompanying drawings in which Figure. 1 isan end view ofiny in proved reanier, Fig, 2 is a longitudinal sec.- tional View on line 22of Fig. lshowing one of the blades and the adjusting; means in side elevation, Fig. 3 isa perspective view of theblades removed from the. headand separatedlfrom one another, Fig. 4 is apee spective view of the head with the blades removed, Fig. 5 is across section of the assembled reamer on the line. 5-5 of Fin. Fig. 6 is a cross section on line 6+6 of Fig. 1, Fig. 7 is a perspective View offthecover 'plate removed from the head,, llig.f8. is a perspective view of oneform of adjusting member, and Fig. 9 is a perspective View of, a somewhat different form. of adjusting member.

The same reference characters designate the same'parts wherever they appear in the drawings. p t M y The parts of thereamercomprise a shank 10, ahead 11, blades 12 and 13, an adjuster M and a coverplate 15. Preferably the shanlrand headaremade in one-piece, and the head is ftIIlilSSlVQ block made out of machlnery steel or cast iron whereby it is sufficiently rigid, but these parts may beother-.

wise constructed if desired. The head is formed with a deep slot 16 extending inward from its, end, and containing; the axis of the shank, the walls of the slot belng parallel and on opposite sides of and equally distant rein a plane .passing through the axis of;

. a head; moved, suflicientlv the shank- Extending from the bottom of this slot and located centrally of the shank is a recess or chamber 17. y

The blades are duplicates of one another and are made fron fiatbars of steel suitable for the formation of metal cutting tools. The two blades laid face to face have a combined width substantially equal to the width of the slot 16 so that they fit freely in such slot. and are firmly supported during the out ting operation by the head, but are free to move endwise, that is, radially of the tool. Thus the faces of the blades which, abut againstone another are substantially radial to the axis of the tool. For convenience of description those faces or sides of, the tools which bear against-one another and are ap proximately in the diametral plane of the tool are, called the inner faces. The cutting edge 18 of each blade is formed by the intersection of'such inner face with the end of theblade, and is made sharp and maintained thus by grinding away such end, the 2 end thus ground beinc: beveled according to the usual practice sufficiently to provide cleartime for the blade.

In the. inner face of each blade is formed a longitudinal groove 19 which serves as a lreyway. and a transverse channel 20 which is formed to receive the adjuster 14, one side of which, designated 21, is inclined. There is also formed in the end of the blade opposite to the cutting edge a longitudinal slot 22 which is made wider. on the outer side so asto provide ledges or lips 23 adapted to embrace the shank and pass under the head of the screw or stud pres ntly des'ribed. In the ICGVWQY of each blade adjacent to the slotted end thereof is set a kev 24, and into the inner face of the said blade at the opposite side of the channel from the slot 2220v i set a stud 25, the latter having a shank which enters the blade and having from the surface of the. blade to admit the ledges 23 of the other blade between thehead and such surface. Conveniently such stud is made as a screw, the shank of which is threaded and enters a tapped hole in theblade, being thereby adjustable so as to bind the blades to gether when they have been assembled in the manner presently described. In assembling the blades they are laid one upon the o her with their inner surfaces in contact and their cutting edges projecting oppositely to one: another, and the key of eachis entered into the keyway of the other. At this time they are so placed that the slotted end of each is between the stud 25 and the slotted end of the other. The blades having been placed together in this manner are then moved longitudinally one upon the other to cause the stud 25 of each to enter the slot 23 of the other, the ledges of the slot passing then under the head of the stud. Upon then screwing down the studs the blades may be clamped together. When the blades have been-thus assembled the transverse channels :20 form a single passageway and the inclined edges 21 are at the opposite sides of this passageway. The adjuster 14: is placed in the passageway so formed. This adjuster is in the form of a double wedge having an inclined edge '26 at one side adapted to bear against the inclined edge 21 ot' the channel in one of the blades, as, for instance, the blade 12, and an oppositely inclined edge :27

adapted similarly to bear s elined edge of the channel in the ether blade. Threaded stems 28 and 29 project from the ends of the wedge. Inthe form of the adjuster shown'in Fig. 8 the construction is essentially that of. two wedges, ea-h having an inclined edge and an edge which is parallel to the stems, these'wedges being overlapped and each being substantially equal in'thickness to the depth of the channel in the blade which it occupies; the central part having twice the thickness of those parts whi' h' project to opposite sides and are formed with theinclined edges. If desired, however, the wedge may be made as shown in .Fig. 9. where it is 01" uniform thickness throughout and the'opposit-e edges of: which areoppositely inclined. I 7

On each of the stems 28 and 29 ofthe wedge are placed a washer 80 and a nut 31, the washer being of greater diameter than the width of thecombined transverse passageway and bearing upon the adjacent part of the b ades. and the nut being screwed on theshank. Theb ades and adjuster. when assembled asdescr bed. are placed inthe 'inthe head wi h the stem 29 and its washer and nut pro ectmg into the chamber 17. The

(over late 15 is placed on the head outside of the blades and secured in a readily removable Inauner bv bolts 32. This cover plate retains the blades in the slot and has a central hole 38 into wh ch-the stem 28 and the washer and nut thereof may be entered. Both this hole and the chamber 17 are greater in "width than the washers which enter them b an amount suilic ent to permit as great endwise movement 0"? the blades as ma be nece sary to center the latter in the hole which is being reamed.

On the outer end of thehead is formed a shallow cylindricalboss 3i whi"h is int rsected by the slot 16 and-enters a complcmental depression 35in the inner surface of the cover plate 15. This boss is adapted to locate the cover member centrally.

It will have become evident from the foregoing description that when the blades are placed in the head in the manner described, they are lo ated symmetrically with respect to the axis of the tool and their cutting edges project at diametrically opposite sides of the tool; and also that the inner faces 01 the blades are radial; while the solid masses of: the head on opposite sides of the slot apply force to the blades in the cutting direction and hold them'up to their work with such firmness and rigidity as to make imrossible any such eitect as chattering ot the blades.

It will be evident also that the tool is adjustable to ream holes differing in diameter through a wide range. for the blades may be set by means of the adjuster 14- to proje"t more or less from the head. In order to make the ne essary adjustments of the blades they are withdrawn from the head after the cover plate has first been removed. and their cutting edges are fO1"G'Cl apart from one another as far as may be required by alternately taking up the nut or stem 29 of the adjuster andslwking oil the nut on stem 28. As this adjustment is made by means of screw threads. it is evident that a very fine and accurate adjustment may be SG"l1IGd. In case adjustment to a smaller diameter of hole than that for which the blades have already been set is required, the blades are first placed with their cutting edges nearer together than the diameter of the hole and are. then spread apart to the required distance by actuation of the adjuster as described. In making these adjustments the screw studs 25 are, of course, slackened suiiiciently to admit of the blades slide readily past one another, and after completion of the adjustment suh studs may be tightened up if desired, although this is not always ne'essarv because the adjuster, with the nuts on the stems thereof, provides a rigid abutme t which presents the res staW-e of the wo k from for ing the cutting edges inwardly. The extent of adjustment is measured by a proper gage or mi rometer caliper, and when effected the blades are p aced in the head and the over plate is put in place.

Since the adjuster acts equally and oppositely on both blades, only one adjustm nt is ne'essarv in order to p t both cutting edges in their proper posit ons; while by rea ou of the fat that the holes 17 and 33 whi h re"eive the stems of the adjuster are larger than the latter or the was e s thereon, the blades have a floating rela ion to the head wh ch enables them to adiu t themsel es to t e hole so that both w ll a"t with eoual effect in ca e there is any minor ariat on in the lengths of the re newive blades. that is, as to the distance of their respecaaeogeoe tive cutting edges from the surfaces on which the adjuster arts.

In addition to the last noted characteristics, this invention has the advantage that the adjustments so made are positively maintained and they cannot be altered ac identally by the resistance of the work. This is due to the. fact that the angle between the axis of thereamer and the in lined abutting fa es ofthe blades' and adjuster is-small, (in one form which I have made-thevalue of this angle is 15 degrees) so'that thecomponent of force applied through the blades to the adjuster is small, and may be less than enough to overcome the fri tion ofthe abutting surfaces. lBut independently?of'this, the adjusting nuts on the stems of the adjuster bear againstthesides of the blades so that accidental movement of the'aadjuster is in any caseimpossible.

Another advantage is that the holding force, when the reamer is held stationary with respect to a rotating Work piece, or the driving power, when the reamer is driven rotatably, is applied to the bladcsu'nyield ingly, due to the massive construction of the headand to the fa t that the width of the head is nearly as great as the length of the blades, so that" pressure is' applied to the" blades at points near their cutting edges;

The advancing faces of the blades are substantially radial to the tool and the angle of their cutting edges is slightly less than a right angle, being enough less to provide proper clearance. This is the ideal condition in a reamer blade, giving suiiicient strength to the cutting edge and at the same time making the edge sharp enough to cut efliiently; and the blade thus arranged cannot chatter.

The two blades with the interposed adjuster form a cutting unit adapted to be inserted in the head as such, that is, without being first mounted in a separate holder. This results in the effect previously described, that one adjustment serves to set both blades equally and oppositelv, and in making it possible to adjust the blades rapidly and easily.

The floating manner in Which the blades are mounted in the head, that is, their capa ity for moving endwise, as previously described. makes the blades se f-adjusting to the hole to be reamed. not only in the case of variations in the blades themselves, but also in case the axis of the tool should not be accurately alined with the axis of the hole.

It is to be understood. of course, that all mechanical variations embodying equivalent ideas of means to those hereinbefore described and hereinafter pointed out in the claims, to accomplish the same or like results, are all within the sons of the protection which I claim, and that such protection is not" restricted tothe specific details here shown.

What I claimand desireto secure by-Let' ters Patent is 1. An adjustable reamer comprising a headhavinga bladeholding slot, 2. pair of blades arranged face to face occupying: said slot, said blades having transverse channels in their abutting face'sof which the side toward the cutting: edge in each blade is'inclined, an adjuster having wedge fates engaged withthe inclinedsidesrof said chan nelsfor adjusting'said bladessimultaneously and oppositely, adjuster bearing on the blades adjacent tothe ends of said channels to:- prevent displace ment of the-adjuster? 12. An adjustable reamer comprising-a head having a slot, a pair of bladesarranged face-to face with their respectively opposite ends projecting from the opposite endsflof the slot andfihaving cutting edges, each of the bladeshavinga transverse channel in the face nextto" the other, whichchannels merge lnto a" passagewaybetween theblades, one side of the channel in each blade being inclined, and said inclined sides in the two blades being opposite to one another, a wedge adjuster occupying saidpassageway and having inclined surfaces bearing on said inclined sides and having stems projecting from each end of the passageway, and nuts threaded on said stems bearing against the blades for adjusting and retaining said aduster;

3. An adjustable reamer comprising a head having a slot, a pair of blades arranged face to face with their respectively opposite ends projecting from the opposite ends of the slot and having cutting edges, each of the blades having a transverse channel in the face next to the other, which channels merge into a passageway between the blades, one side of the channel in each blade being in clined, and said inclined sides in the two blades being opposite to one another, a wedge adjuster occupying said passageway and having inclined surfaces bearing on said inclined sides and havingstems projecting from each end of the passageway, nuts threaded on said stems bearing against the blades for adjusting and retaining said adjuster, and a cover member attached to the and holding means for said head overlying said slot and retaining the an inclined bounding face, each blade having also a slot or notch with flanking ledges opening inward fromthe end opposite to that which carries the cutting edge, a stud projecting from theafore-mentioned face of each blade into the slot of the other blade and having a head cooperating with the ledges of the slot to clamp the blades together, and a key set into the keyway of each blade near one end, and fitting slidingly the keyway of the other blade.

5. A complimental pair of adjustable reamer blades having abutting surfaces in contact and having cutting edges on their respectively opposite ends, means for hold ing said blades together arranged to permit movement of each longitudinally of the other, each blade having in the side next to the other a channel with an inclined bounding edge and an expander occupying said channel and having inclined surfaces which bear upon the opposite inclined surfaces of the respective blades, and means for moving said expander so as to adjust said blades to vary the distance between their cutting edges, said adjusterhaving stems on opposite ends projecting from the blades, and nuts threaded on said stems respectively arranged to bear'on the adjacent sides of the blades for shifting said adjuster and maintaining the ad ustments thereof.

6. A complemental pair of reamer blades other for additionally guiding such rela- A tive movement, and an adjuster arranged between the blades, the latter having channels which together form a passageway containing such adjuster, the channel in one blade having an inclined boundary at one side,'and that in the other blade having an inclined boundary at the other side, and the adjuster having inclined surfaces to bear upon said boundaries and thereby adjust the blades in consequence of its movements.

In testimony whereof I have ailixed my signature.

CHARLES P. HOWK.

#{Jopies ot this patent may be obtained for five cents each, by addressing the Commissioner 0! Patents.

' Washington, D. O." 

